To improve elevator performance in delivering passengers to destination floors, recent focus has been on automatic call placement systems, typically utilizing some sort of electromagnetic transmitter to place the call. Some of the systems are passive, requiring no activity on behalf of the potential passenger to place the call. In such a case, an elevator call is placed by a transponder, such as a transmitter worn by the passenger responding to a beacon. In order to move passengers quickly out of the lobby, the calls are placed as early as possible. However, this results in placement of numerous false calls, since not all persons passing through the lobby or other elevator corridor, intend to use the elevator.
In U.S. Pat. No. 4,662,479, a measurement means tracks the position of a passenger, and places a destination call if the passenger enters the elevator, but cancels the call if the passenger wanders away from the elevator. This is extremely difficult to implement whenever there are numerous passengers.
In commonly owned U.S. patent application Ser. No. 09/189,161 filed on Nov. 9, 1998, now U.S. Pat. No. 6,109,396, a passenger proceeding toward the elevators will automatically cause a "far call" to be registered, to cause an elevator to approach the floor of the passenger, but the car does not stop unless the passenger reaches the proximity of an elevator, where a "near call" is placed for him.